Molecule-Designer description

The R/S system is used for a description of chiral molecules. Designations also exist for pro-chiral molecules, (where replacement of one group will produce a chiral center), pro-R, pro-S, as well as faces of planes containing atoms, re and... 

The design of fluorescence-based detection systems for small molecules is influenced immediately by the fact that the vast majority of these target analytes are nonfluorescent. Therefore, sensors are required that probe the analyte and incorporate fluorophores which respond sensitively to the probe-analyte interaction. As stated above, in type I sensors these fluorophores are coupled to the sensor unit of the reporter. A vast array of fluorescent molecules is known. Here we give a brief overview of these fluorophores by family—small molecules, proteins, and the new fluorescent nanomaterials—and comment on how they may be incorporated into sensors for small molecules. The description of the sensor units is usually unique to the analyte of interest and is detailed in Section 6.3. 

The R, S convention is a scheme which has largely superseded the D, i. system to denote configuration about a chiral centre in a molecule. The convention allows unequivocal designation of the absolute configuration in a description of the positions in space of ligands attached to a chiral centre, in relation to an agreed standard of chirality like a right-hand helix. 

B and W J Howe 1991. Computer Design of Bioactive Molecules - A Method for Receptor-Based Novo Ligand Design. Proteins Structure, Function and Genetics 11 314-328. i H L 1965. The Generation of a Unique Machine Description for Chemical Structures - A hnique Developed at Chemical Abstracts Service. Journal of Chemical Documentation 5 107-113. J 1995. Computer-aided Estimation of Symthetic Accessibility. PhD thesis. University of Leeds, itan R, N Bauman, J S Dixon and R Venkataraghavan 1987. Topological Torsion A New )lecular Descriptor for SAR Applications. Comparison with Other Descriptors. Journal of emical Information and Computer Science 27 82-85. 

The final part is devoted to a survey of molecular properties of special interest to the medicinal chemist. The Theory of Atoms in Molecules by R. F.W. Bader et al., presented in Chapter 7, enables the quantitative use of chemical concepts, for example those of the functional group in organic chemistry or molecular similarity in medicinal chemistry, for prediction and understanding of chemical processes. This contribution also discusses possible applications of the theory to QSAR. Another important property that can be derived by use of QC calculations is the molecular electrostatic potential. J.S. Murray and P. Politzer describe the use of this property for description of noncovalent interactions between ligand and receptor, and the design of new compounds with specific features (Chapter 8). In Chapter 9, H.D. and M. Holtje describe the use of QC methods to parameterize force-field parameters, and applications to a pharmacophore search of enzyme inhibitors. The authors also show the use of QC methods for investigation of charge-transfer complexes. 

Cryostats have been much used in small-molecule crystallography because they allow rapid cooling to very low temperatures with minimal cold gas consumption and offer great advantages in the area of frost prevention. Unfortunately, most designs employ beryllium shrouds or other nontransparent material, and are of a size which does not lend itself to crystals mounted in capillary tubes and flow cells. A recent advance is the description of a Mylar cryostat specifically designed for... 

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